package com.atguigu.flink.java.chapter_7;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.common.functions.ReduceFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.windowing.assigners.TumblingProcessingTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.util.Collector;

import java.util.Arrays;

/**
 * @Author lizhenchao@atguigu.cn
 * @Date 2020/12/12 20:29
 */
public class Flink07_Chapter07_Reduce {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment().setParallelism(2);
        env
          .socketTextStream("mac", 9999)
          .flatMap(new FlatMapFunction<String, Tuple2<String, Long>>() {
              @Override
              public void flatMap(String value, Collector<Tuple2<String, Long>> out) throws Exception {
                  Arrays.stream(value.split("\\W+")).forEach(word -> out.collect(Tuple2.of(word, 1L)));
              }
          })
          .keyBy(t -> t.f0)
          .window(TumblingProcessingTimeWindows.of(Time.seconds(5)))
          .reduce(new ReduceFunction<Tuple2<String, Long>>() {
              @Override
              public Tuple2<String, Long> reduce(Tuple2<String, Long> value1, Tuple2<String, Long> value2) throws Exception {
                  System.out.println(value1 + " ----- " + value2);
                  // value1是上次聚合的结果. 所以如果是第一个元素, 这个函数不会进来
                  return Tuple2.of(value1.f0, value1.f1 + value2.f1);
              }
          })
          .print();


        env.execute();
    }
}
